Correct Understanding of Big Bang Theory

[Lord Draco]

Is this correct?

Before the big bang or at the moment of the big bang(since we don't know what happened before the big bang), from my understanding it is believed that everything in the universe was all condensed into a singularity, a single point of all the energy of the universe. is this correct?

 

[Garth]

This is correct according to pure GR, at the moment of the BB the universe was condensed into a singularity of infinite density. However at some point, as one approaches the BB under time reversal, GR is expected to yield to quantum effects; what these effects might do can only be predicted by a quantum gravity theory, unfortunately we do not have such a theory - yet.

Garth

 

[mathman]

Garth's description is also relevant to the question of what goes on inside a black hole. Relativity predicts a condensation to a point singularity, but quantum theory gets in the way and we really don't know what goes on.

 

[JesseM]

Even in ordinary general relativity, it's not necessarily true that a singularity is a "single point". In a model where the universe is spatially infinite, you can say that the density goes to infinity at the singularity, and you can say that the distance between any two points which are some finite distance apart at a later time goes to zero at the singularity, but I don't think it necessarily makes sense to call the singularity a "point", its size wouldn't be well-defined (it's sort of like the question, 'what's zero times infinity'?)